1. Field
The present disclosure is directed to an automatic exposure algorithm in imaging devices such as digital cameras. More particularly, the present disclosure is directed to a method and apparatus for synchronizing auto exposure between chromatic pixels and panchromatic pixels in a camera system.
2. Introduction
Presently, people enjoy taking pictures of friends, family, children, vacations, flowers, landscapes, and other scenes using digital cameras. Some cameras now use panchromatic, such as clear, pixels along with chromatic pixels, such as Red, Green, and Blue (RGB) pixels for improved image quality. In such single or multiple camera systems, the spectral response of chromatic pixels is lower than panchromatic pixels. This means the received light at the same exposure time is different between chromatic pixels and panchromatic pixels without adjusting the exposure of the different types of pixels. Unfortunately, such a difference in exposure results in underexposed chromatic pixels and/or overexposed panchromatic pixels. For example, if an exposure for a scene is set for the chromatic pixels, the panchromatic pixels will be overexposed. Also, if an exposure for a scene is set for the panchromatic pixels, the chromatic pixels will be underexposed.
Thus, there is a need for a method and apparatus for synchronizing auto exposure between chromatic pixels and panchromatic pixels in a camera system.